The expansion pack lets players fight their way through Blackrock Mountain, a notorious location in World of Warcraft. The Mountain is split into five different wings, each with its own set of A.I. bosses to challenge. The bosses possess new abilities that will require specific strategies (and decks) to defeat.

Blizzard will roll out one wing of Blackrock Mountain per week. The first wing, debuting today, is called Blackrock Depths. Here's a breakdown of each boss in Blackrock Depths and their rewards:

If you clear Blackrock Depths, you'll also unlock the Legendary card for Emperor Thaurissan. He's 5/5 minion that reduces the cost of cards in your hand by 1 mana at the end of your turn.

Clearing the wing also unlocks access to Class Challenges for the Hunter and Mage. These Challenges task you with beating a boss with that class and a specific deck. Here's what you'll earn by completing each encounter:

Unlike previous single-player expansion Curse of Naxxramas, Blackrock Mountain doesn't have a free wing. You'll need to pay to unlock Blackrock Depths along with the four later parts of the expansion. Each wing costs 700 gold, or $6.99 USD. The price-per-wing is a bit lower if you buy in bulk:

All 5 Wings - $24.99

Remaining 4 Wings - $19.99

Remaining 3 Wings - $14.99

Remaining 2 Wings - $9.99

Remaining 1 Wings - $4.99

The entire Blackrock Mountain expansion will give you 31 new cards by defeating all of its challenges. Beating bosses is the only way to earn them, though. There won't be any new booster packs like with the Gnomes vs Gnomes expansion.